Muhammad Ali Dies

Muhammad Ali, widely hailed as the greatest heavyweight boxer in the sport’s history, died late Friday night after being hospitalized in Arizona Thursday with a respiratory issue.

Ali, 74, had suffered from Parkinson’s disease since the 1980s.

“After a 32-year battle with Parkinson’s disease, Muhammad Ali has passed away at the age of 74. The three-time World Heavyweight Champion boxer died this evening,” family spokesperson Bob Gunnell said in a statement.

Ali's prowess in the ring and his personality and social activism make him one of the most recognizable sports figures of the last century.

He secured an Olympic gold medal in the 1960 Summer Games and became one of the youngest heavyweight champions of all time, stunning the boxing world with a knockout of Sonny Liston to claim the title in 1964 at 22.

It marked the first of three times Ali would win the heavyweight title.

Shortly after the native of Louisville defeated Liston, Ali became a cog in both the civil rights and anti-war movement. Ali changed his name from Cassius Clay after he joined the Nation of Islam, and he was convicted of draft evasion in 1967 after he refused to fight in the Vietnam War because of religious beliefs.

His opposition to the Vietnam War cost him the belt and led to a three-year ban from boxing. His conviction for dodging the Vietnam War draft was overturned by the Supreme Court in 1971.

Ali returned to the ring in 1970 and suffered his first pro loss a year later in a title bout against Joe Frazier, who won via unanimous decision.

It was the first of three memorable fights against Frazier – with Ali winning the last two.

Ali reclaimed the heavyweight belt against George Foreman in one of the most storied events in sports history, "The Rumble in the Jungle" in 1974. Ali employed the "rope-a-dope," in which he allowed Foreman to tire himself out as Ali absorbed punch after punch, before he claimed the bout in Zaire -- now known as the Democratic Republic of the Congo -- with a knockout.

In 1978, a clearly overweight Ali lost his title to Leon Spinks but won it back in a rematch six months later, making him the first fighter to win the heavyweight title three times.

Ali retired from boxing in 1981 with a 56-5 record, three of the losses coming in his final four fights. He had 37 knockouts.

Ali was diagnosed with Parkinson's disease three years after his retirement. Family members believed his years of boxing contributed to the disease.

After his retirement, he concentrated on philanthropy and social activism.

He was admitted for medical treatment several times in recent years, including to treat pneumonia in December 2014.